A survey of female commercial sex workers (CSW) in Iloilo City, Philipines, was conducted in October and November 1995 to determine the level of knowledge, attitudes, and preventive practices regarding HIV/AIDS to guide future education programs. CSWs in the Philippines were categorized as registered or freelance. Registered CSWs included "hospitality girls" from licensed bars, night clubs, and massage parlors who have registered with the local social hygiene clinic (SHC). Freelance CSWs are not registered. 110 registered and 46 freelance CSWs were surveyed. We compared demographic data, scores from a basic knowledge test, and preventive practices between registered and freelance CSWs. Demographic data indicate that registered CSWs often originate from provinces outside of the Visayan Islands (25%) and most have never been married (93%). Freelance CSWs included more married (11%) and separated (11%) women from nearby cities. Knowledge test scores of registered and freelance CSWs were not significantly different. 90-96% of CSWs correctly answered questions regarding modes of transmission. However, 25% still believed it is possible to contract AIDS from using a public restroom. Registered and freelance CSWs believed their risks for AIDS to be equally great. However, 38% of freelance CSWs admit to never or almost never using condoms compared to 15% of registered CSWs. Licensed establishments and a support staff at the social hygiene clinic may provide a relatively structured working environment, giving registered CSWs security and confidence to insist on condom use. In most cases, condom use seems to depend on male customer compliance, and CSWs, especially freelancers, cannot afford to insist on condom use. The CSWs indicated that they learned most about AIDS through health personnel and television.